public static function getImageLoaderURL($url, &$width, &$height) {
        if ($url && strpos($url, '/photo-placeholder.gif') !== FALSE) {
            $url = ''; // skip empty placeholder image 
        }
        
        if ($url) {
            switch ($GLOBALS['deviceClassifier']->getPagetype()) {
                case 'compliant':
                    $width = 140;
                    $height = 140;
                    break;
                case 'basic':
                case 'touch':
                default:
                    $width = 70;
                    $height = 70;
                    break;
            }
          
            $extension = pathinfo($url, PATHINFO_EXTENSION);
            if ($extension) { $extension = ".$extension"; }
  
            $url = ImageLoader::precache($url, $width, $height, 'LDAP_'.md5($url).$extension);
        }
        
        return $url;
    }